<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <title>Document</title>
  <style>
    #box{width: 200px;height:300px;background: red}
  </style>
</head>
<body>
  <div id="box">
    <span>1</span>
    <span>2</span>
    <span class="three">3</span>
    <span>4</span>
    <span>5</span>
  </div>
</body>
<script>

  var box = document.querySelector("#box")
  var three = document.querySelector("#box .three")

  // 删除指定元素
  // three.remove();

  // 根据父元素删除指定元素
  box.removeChild( three );


  
</script>
</html>